The selection of routes is an issue of utmost importance in data networks. Cost based routing strategies arise as a result of network performance optimization or through the incorporation of Quality of Service (QoS) requirements as part of the routing process. In such networks, routing is based on a cost-based scheme which admits an arriving request on a minimum cost route if the associated cost of the route does not exceed the cost of the request. A network may be modeled as a graph, wherein routers and switches are represented by nodes and physical links between the routers and switches are represented by edges. Each edge is assigned a cost associated with the cost of sending a packet across that link. The total cost of a path is the sum of the cost of the edges in the path. A determination is made regarding the least-cost path to use to route a packet across the network.